Sheet-form transparent molding, transparent screen comprising same, and image projection device comprising same

ABSTRACT

Provided is a sheet-form transparent molding for use for a transparent screen, satisfying both visibilities of a projected light and a transmitted light by anisotropically scattering and reflecting the projected light emitted from a light source. A sheet-form transparent molding according to the present invention comprises a transparent light scattering layer comprising a resin and bright flake-form microparticles.

TECHNICAL FIELD

The present invention relates to a sheet-form transparent molding,capable of satisfying both visibilities of projected light andtransmitted light by anisotropically scattering and reflecting theprojected light, a transparent screen comprising the same, and an imageprojection device comprising the same.

BACKGROUND ART

Conventionally, a combination of a Fresnel lens sheet and a lenticularlens sheet has been used for a projector screen. In recent years, ademand for displaying merchandise information, advertisement, or thelike by projection on a shop window of a department store or the like, atransparent partition of an event venue, or the like while maintainingthe transparency thereof is growing. It is said that, in the future, ademand for a highly transparent projection type image display screenwhich is used for a head-up display, a wearable display, or the likewill be further increasing.

However, since a conventional projector screen has a low transparency,there is a technical problem that such projector screen cannot beapplied to a transparent partition, or the like. Therefore, variousscreens are proposed that are capable of attaining a high transparency.For example, there is proposed a reflection type screen characterized inthat 7 parts by weight of an aluminum flake and 25 parts by weight ofpearl pigment flakes, which are based on mica coated with titaniumdioxide, are mixed and used as a filler for an ink which is printed orcoated on a plastic film or a sheet to form a light reflection layer(see Patent Document 1). A reflection type screen for a projector isproposed, characterized in that an optical diffusion layer is providedon the substrate, comprising from 10 to 80 by weight of a flake-formaluminum paste of a non-refilling type as a light reflecting agent,based on 100 parts by weight of a binder resin, and additionally 50% byweight or more of a light diffusion agent based on the light diffusionagent (see Patent Document 2). Further, a reflection type screen isproposed, in which an optical diffusion layer is laminated on a lightreflection substrate, formed by a continuous layer composed of atransparent resin and a dispersion layer composed of anisotropictransparent particles (see Patent Document 3).

RELATED ART DOCUMENTS Patent Documents

Patent Document 1 Japanese Unexamined Patent Application Publication No.1991-119334

Patent Document 2 Japanese Unexamined Patent Application Publication No.1998-186521

Patent Document 3 Japanese Unexamined Patent Application Publication No.2004-54132

SUMMARY OF THE INVENTION Problems to be Solved by the Invention

However, the present inventors found the following technical problems inPatent Documents 1 to 3. The reflection type screen described in PatentDocument 1 have a technical problem that an image cannot be clearlyvisualized due to glare of a coating film since the flake particles arecoated on a substrate surface in a high concentration, and that aperspective view is impossible since a white-colored vinyl chloride filmis used for the substrate. The reflection type screen described inPatent Document 2 comprises a high-concentration, 10 to 80 by weight, ofthe flake-form aluminum paste as the light reflecting agent; thereforehave a technical problem that a perspective view is impossible in theobtained film. The reflective screen described in Patent Document 3 hasa technical problem that, since the anisotropic transparent particlesdispersed in the dispersion layer are non-metallic particles of mica,talc, and montmorillonite, and especially, talc and montmorillonite areclay-based particles, it has a low regular reflectance and cannot besuitably used as a reflection type transparent screen.

Means for Solving the Problems

The present invention has been made in view of the above-describedtechnical problems, and an object of the present invention is to providea sheet-form transparent molding having excellent visibility of aprojected light due to anisotropic scattering and reflecting of theprojected light, and further having a wide viewing angle and excellentvisibility of a transmitted light. An object of the present invention isalso to provide a transparent screen comprising the sheet-formtransparent molding and an image projection device comprising thesheet-form transparent molding or the transparent screen and aprojection device. A transparent sheet mentioned here may be atransmission or a reflection type screen. A transmission type screen isa screen that an image can be visualized by setting a projection deviceon the opposite side of a viewer against the screen as shown in FIG. 2,and a reflection type screen is a screen that an image can be visualizedby setting a projection device on the viewer side (the same side as theviewer against the screen) as shown in FIG. 2.

In order to solve the above described technical problems, the presentinventors intensively studied to find that the above described technicalproblems can be solved by dispersing bright flake-form microparticles ina resin and forming a transparent light scattering layer and as aresult, a sheet-form transparent molding can be obtained which can besuitably used for a transparent screen. The present invention has beencompleted based on such findings.

That is, according to one aspect of the present invention, there isprovided a sheet-form transparent molding comprising a transparent lightscattering layer comprising a resin and bright flake-formmicroparticles.

According to one aspect of the present invention, an average diameter ofprimary particles of the bright flake-form microparticles is preferablyfrom 0.01 to 100 μm.

According to one aspect of the present invention, regular reflectance ofthe bright flake-form microparticles is preferably 12% or more.

According to one aspect of the present invention, an average aspectratio of the bright flake-form microparticles is preferably from 3 to800.

According to one aspect of the present invention, the bright flake-formmicroparticles are preferably metallic particles selected from the groupconsisting of aluminum, silver, copper, platinum, gold, titanium,nickel, tin, tin-cobalt alloy, indium, chromium, titanium oxide,aluminum oxide, and zinc sulfide, a bright material of glass coated withmetallic oxide or metal, or a bright material of natural or syntheticmica coated with metal or metallic oxide.

According to one aspect of the present invention, the resin ispreferably at least one selected from the group consisting of an acrylicresin, a polyester resin, a polyolefin resin, a vinyl resin, apolycarbonate resin, and a polystyrene resin.

According to one aspect of the present invention, the content of thebright flake-form microparticles is preferably from 0.0001 to 5.0% bymass based on the resin.

According to one aspect of the present invention, the transparent lightscattering layer preferably further comprises substantially sphericalmicroparticles.

According to one aspect of the present invention, the difference betweena refractive index n₂ of the substantially spherical microparticles anda refractive index n₁ of the resin preferably satisfies the followingformula (1):

|n ₁ −n ₂|≧0.1  (1).

According to one aspect of the present invention, the substantiallyspherical microparticles are preferably at least one selected from thegroup consisting of zirconium oxide, titanium oxide, zinc oxide, ceriumoxide, barium titanate, strontium titanate, magnesium oxide, calciumcarbonate, barium sulfate, diamond, a cross-linked acrylic resin, across-linked styrene resin, and silica.

According to one aspect of the present invention, a median diameter ofprimary particles of the substantially spherical microparticles ispreferably from 0.1 to 500 nm.

According to one aspect of the present invention, the content of thesubstantially spherical microparticles is preferably from 0.0001 to 2.0%by mass based on the resin.

According to one aspect of the present invention, the sheet-formtransparent molding preferably has a total light transmittance of 70% orhigher.

According to one aspect of the present invention, the sheet-formtransparent molding preferably has a diffusion transmittance from 1.5%to 50% or less.

According to one aspect of the present invention, the sheet-formtransparent molding preferably has an image clarity of 70% or higher.

According to one aspect of the present invention, the sheet-formtransparent molding preferably further comprises on one side atransparent reflection layer having a refractive index n₃, higher thanthe refractive index n₁.

According to one aspect of the present invention, the refractive indexn₃ of the transparent reflection layer is preferably 1.8 or higher.

According to one aspect of the present invention, the transparentreflection layer preferably comprises at least one selected from thegroup consisting of titanium oxide, niobium oxide, cerium oxide,zirconium oxide, indium tin oxide, zinc oxide, tantalum oxide, zincsulfide, and tin oxide.

According to one aspect of the present invention, an optical filmthickness represented by the product of the refractive index n₃ and filmthickness d is preferably from 20 to 400 nm.

According to one aspect of the present invention, the sheet-formtransparent molding is preferably for a transmission type transparentscreen.

According to one aspect of the present invention, the sheet-formtransparent molding is preferably for a reflection type transparentscreen.

In another aspect of the present invention, there is provided atransmission type transparent screen, comprising the above-describedsheet-form transparent molding.

In another aspect of the present invention, there is provided areflection type transparent screen, comprising the above-describedsheet-form transparent molding.

In another aspect of the present invention, there is provided alaminated body, comprising the above described sheet-form transparentmolding, transmission type transparent screen, or a reflection typetransparent screen.

In another aspect of the present invention, there is provided a memberfor a vehicle, comprising the above described sheet-form transparentmolding, transmission type transparent screen, or a reflection typetransparent screen.

In another aspect of the present invention, there is provided a memberfor a house, comprising the above described sheet-form transparentmolding, transmission type transparent screen, or a reflection typetransparent screen.

In another aspect of the present invention, there is provided an imageprojection device, comprising the above described sheet-form transparentmolding or transmission type transparent screen, and a projectiondevice.

In another aspect of the present invention, there is provided an imageprojection device, comprising the above described sheet-form transparentmolding or reflection type transparent screen, and a projection device.

Effects of the Invention

When a sheet-form transparent molding of the present invention is usedas a transparent screen, clear image can be projected on the transparentscreen by scattering and reflecting a projected light anisotropicallywithout compromising transparency and in addition, the viewing angle isexcellent. That is, the sheet-form transparent molding of the presentinvention can satisfy both visibilities of a projected light and atransmitted light, and can be used suitably as a transmission typetransparent screen as well as a reflection type transparent screen.Further, the sheet-form transparent molding of the present invention canbe suitably used for a member for a vehicle or a house. The sheet-formtransparent molding of the present invention can be suitably used as alight guide plate used in an image display device, an image projectiondevice, a light source for a scanner, or the like.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a cross-sectional schematic diagram in the thickness directionof one embodiment of a sheet-form transparent molding according to thepresent invention.

FIG. 2 is a schematic diagram of one embodiment of a transparent screenand an image projection device according to the present invention.

MODE FOR CARRYING OUT THE INVENTION <Sheet-form Transparent Molding>

A sheet-form transparent molding according to the present inventioncomprises a transparent light scattering layer. The sheet-formtransparent molding according to the present invention enables aperspective view and can be suitably used as a transparent screen. Thesheet-form transparent molding according to the present invention hasexcellent visibility of a projected light since the projected light isanisotropically scattered and reflected, has a wide viewing angle, andfurther has high transparency and excellent visibility of a transmittedlight. Such a sheet-form transparent molding can be used suitably as areflection type screen used for a head-up display, a wearable display,or the like. In the present invention, the term “transparent” meanstransparent in the degree that a transmission visibility depending onthe applications is attained and also includes being “translucent”.

FIG. 1 is a cross-sectional schematic diagram in the thicknessdirection, illustrating one embodiment of a sheet-form transparentmolding according to the present invention. The transparent sheet-formmolding consists of a transparent light scattering layer 11 consistingof bright flake-form microparticles 12 dispersed in a resin 14. Such alight scattering layer 11 may comprise substantially sphericalmicroparticles 13. A two-ply constitution comprising the lightscattering layer 11 and a transparent reflection layer 15, or a layeredbody of a multi-ply constitution further comprising other layers such asa protection layer, a backing layer, an adhesive layer, a reflectionprotection layer, or the like, may be possible.

The haze value of the sheet-form transparent molding is preferably 50%or less, more preferably from 1% to 40% or less, more preferably from1.3% to 30% or less, and still more preferably from 1.5% to 20% or less.The total light transmittance of the sheet-form transparent molding ispreferably 70% or higher, more preferably 75% or higher, stillpreferably 80% or higher, and still more preferably 85% or higher. Thediffusion transmittance of the sheet-form transparent molding ispreferably from 1.5% to 50% or less, more preferably from 1.7% to 45% orless, more preferably from 1.9% to 40% or less, and still morepreferably from 2.0% to 38% or less. The transparency will be high andthe transmission visibility will be more improved if the haze value andthe total light transmittance are within the above-described ranges, andwhen the diffusion transmittance is within the above-described range,the entering light will be efficiently diffused and the viewing anglecan be improved; resulting in an excellent performance as a screen. Inthe present invention, the haze value, the total light transmittance,and the diffusion transmittance of the sheet-form transparent moldingcan be measured by using a turbidimeter (Part No.: NDH-5000;manufactured by NIPPON DENSHOKU INDUSTRIES CO., LTD.) in accordance withJIS-K-7361 and JIS-K-7136.

The image clarity of the laminated body is preferably 70% or higher,more preferably 75% or higher, further preferably 80% or higher, stillmore preferably 85% or higher, and particularly preferably 90% orhigher. An image transmitted through a transparent screen to be seenwill be remarkably clear when the image clarity of the laminated body iswithin the above-described range. In the present invention, the imageclarity is a value of definition (%) when measured with an optical combhaving a width of 0.125 mm in accordance with JIS K7374.

The reflected frontal luminous intensity of the sheet-form transparentmolding is preferably from 3 to 60 or less, more preferably from 4 to 50or less, and still preferably from 4.5 to 40 or less. The transmittedfrontal luminous intensity of the sheet-form transparent molding ispreferably 1.5 or higher, more preferably 2.0 or higher, and stillpreferably from 3.0 to 50 or less. When the reflected and transmittedfrontal luminous intensity of the sheet-form transparent molding arewithin the above-described ranges, the brightness of the reflectionlight will be high, resulting in an excellent performance as areflection type screen. In the present invention, the progression ratesof the reflected and transmitted frontal luminous intensities are valuesmeasured in such way as follows.

(Reflected Frontal Luminous Intensity)

The reflected frontal luminous intensity is measured by using agoniophotometer (Part No.: GC5000L; manufactured by NIPPON DENSHOKUINDUSTRIES CO., LTD.). An entering to angle of a light source is set to45 degrees, and a reflected light intensity in the direction of 0 degreewhen a standard white-colored plate with whiteness degree of 95.77 wasplaced on the measuring stage is 100. When a sample is measured, theentering angle of the light source is set to 15 degrees and theintensity of the reflected light in the direction of 0 degree ismeasured.

(Transmitted Frontal Luminous Intensity)

The transmitted frontal luminous intensity is measured by using agoniophotometer (Part No.: GC5000L; manufactured by NIPPON DENSHOKUINDUSTRIES CO., LTD.). An entering angle of a light source is set to 0degree, and a transmitted light intensity in the direction of 0 degreewith nothing placed on the measuring stage is 100. When a sample ismeasured, the entering angle of the light source is set to 15 degreesand the intensity of the transmitted light in the direction of 0 degreeis measured.

The thickness of the sheet-form transparent molding is not particularlylimited; however, in view of purposes, productivity, handling, andportability, it is preferably from 0.1 μm to 20 mm, more preferably from0.2 μm to 15 mm, and still preferably from 1 μm to 10 mm. In the presentinvention, a “sheet-form transparent molding” includes moldings ofvarious thickness such as what is called a film, a sheet, a coated filmbody formed by coating on a substrate, a plate (a plate-form molding),or the like.

(Transparent Light Scattering Layer)

The transparent light scattering layer comprises a resin and brightflake-form microparticles. The use of bright flake-form microparticlesas below will anisotropically scatter and reflect the light in thetransparent light scattering layer, and thus the viewing angle can beimproved.

The thickness of the transparent light scattering layer is notparticularly limited; however, in view of purposes, productivity,handling, and portability, it is preferably from 0.1 μm to 20 mm, morepreferably from 0.2 μm to 15 mm, and still preferably from 1 μm to 10mm. The transparent light scattering layer may be the sheet-formtransparent molding or may be a coated film formed on a substratecomprising glass, a resin, or the like. The transparent light scatteringlayer may be of a single-ply constitution or a multi-ply constitution,formed by layering two or more layers with coating or by stickingtogether two or more sheet-form transparent moldings with an adhesive,or the like.

(Resin)

As a resin forming the transparent light scattering layer, a highlytransparent resin is preferably used in order to obtain a sheet-formtransparent molding of a high transparence. For a highly transparentresin, a thermoplastic resin such as an acrylic resin, an acrylicurethane resin, a polyester acrylate resin, a polyurethane acrylateresin, an epoxy acrylate resin, a polyester resin, a polyolefin resin, aurethane resin, an epoxy resin, a polycarbonate resin, a celluloseresin, an acetal resin, a vinyl resin, a polystyrene resin, a polyamideresin, a polyimide resin, a melamine resin, a phenol resin, a siliconeresin, a polyarylate resin, a polyvinyl alcohol resin, a polyvinylchloride resin, a poly sulfone resin, and a fluorocarbon resin; athermoset resin; an ionizing radiation-curable resin; or the like can beused. Among these, a thermoplastic resin is preferably used in view offormability of the sheet-form transparent molding but without specificlimitation. As thermoplastic resins, preferably, an acrylic resin, apolyester resin, a polyolefin resin, a vinyl resin, a polycarbonateresin, and a polystyrene resin are used, and more preferably, apolymethyl methacrylate resin, a polyethylene terephthalate resin, apolyethylene naphthalate resin, a polypropylene resin, a cycloolefinpolymer resin, a cellulose acetate propionate resin, a polyvinyl butyralresin, a polycarbonate resin, and a polystyrene resin are used. Theseresins may be used singly, or in combination of two or more kindsthereof. The ionizing radiation-curable resin includes an acrylic resin,a urethane resin, an acrylic urethane resin, an epoxy resin, and asilicone resin. Among these, those having an acrylate functional group,for example, those containing a relatively high amount of amonofunctional monomer such as ethyl (meth)acrylate, ethylhexyl(meth)acrylate, styrene, methyl styrene, N-vinylpyrrolidone and apolyfunctional monomer, such as polymethylolpropane tri(meth)acrylate,hexane diol (meth)acrylate, tripropylene glycol di(meth)acrylate,diethylene glycol di(meth)acrylate, pentaerythritol tri(meth)acrylate,dipentaerythritol hexa(meth)acrylate, 1,6-hexane diol di(meth)acrylate,neopentyl glycol di(meth)acrylate as an oligomer or a prepolymer of apolyester resin, a polyether resin, an acrylic resin, an epoxy resin, aurethane resin, an alkyd resin, a spiroacetal resin, a polybutadieneresin, a polythiol polyene resin, a (meth)acrylate of a polyfunctionalcompound such as a polyalcohol and a reactivity diluent having arelatively low molecular weight are preferable. The ionizingradiation-curable resin may be obtained by mixing a thermoplastic resinand a solvent. The thermoset resin includes a phenol resin, an epoxyresin, a silicone resin, a melamine resin, a urethane resin, and a urearesin. Among these, an epoxy resin and a silicone resin are preferable.

(Bright Flake-Form Microparticles)

As bright flake-form microparticles, a bright material processable to aflake form can be suitably used. The regular reflectance of the brightflake-form microparticles is preferably 12.0% or higher, more preferablyfrom 15.0% to 100% or less, and still preferably from 20.0% to 95.0% orless. In the present invention, the regular reflectance of the brightflake-form microparticles is measured in such way as follows.

(Regular Reflectance)

The regular reflectance is measured by using a spectrophotometer (PartNo.: CM-3500d; manufactured by KONICA MINOLTA INC.). A powder materialdispersed in an appropriate solvent (water or methyl ethyl ketone) iscoated on a glass slide such that the film thickness will be 0.5 mm ormore and dried. Using this obtained glass plate with the coated film,the regular reflectance of the film-coated part from the glass surfaceis measured.

As the bright flake-form microparticles, for example, metallicmicroparticles such as aluminum, silver, platinum, gold, copper,titanium, nickel, tin, tin-cobalt alloy, indium, and chromium, ormetallic microparticles consisting of titanium oxide, aluminum oxide,and zinc sulfide, a bright material of glass coated with metal or metaloxide, or a bright material of natural or synthetic mica coated withmetal or metal oxide can be used, depending on the kind of resin to bedispersed in.

The average diameter of the primary particles of the bright flake-formmicroparticles is preferably from 0.01 to 100 μm, more preferably from0.05 to 80 μm, still preferably from 0.1 to 50 μm, and still morepreferably from 0.5 to 30 μm. The average aspect ratio (=averagediameter/average thickness of the bright flake-form microparticles) ofthe bright flake-form microparticles is preferably from 3 to 800, morepreferably from 4 to 700, still preferably from 5 to 600, still morepreferably from 10 to 500. When the sheet-form transparent molding isused as the transparent screen with the average diameter and the averageaspect ratio of the bright flake-form microparticles being within theabove-described ranges, a clear image can be projected since asufficient scattering effect of the transmitted light is obtainedwithout compromising the transmission visibility. In the presentinvention, the average diameter of the bright flake-form microparticlesis measured using a laser diffraction particle size distributionmeasuring device (Part No.: SALD-2300; manufactured by ShimadzuCorporation). The average aspect ratio was calculated from an SEM (TradeName: SU-1500; manufactured by Hitachi High Technologies Corporation)image.

As for the bright flake-form microparticles, those commerciallyavailable may be used, and for example, aluminum powder manufactured byDaiwa Kinzoku Kogyo Co., Ltd., METASHINE, glass coated with metal,manufactured by MATSUO SANGYO CO., LTD., or the like can be suitablyused.

The content of the bright flake-form microparticles in the transparentlight scattering layer can be appropriately adjusted, depending on theregular reflectance of the bright flake-form microparticles, andpreferably is from 0.0001 to 5.0% by mass, preferably from 0.0005 to3.0% by mass, more preferably from 0.001 to 1.0% by mass, based on theresin. The visibilities of the projected light and the transmitted lightcan be improved by dispersing the bright flake-form microparticles inthe resin in a low concentration as the range described above andforming the transparent light scattering layer to anisotropicallyscatter and reflect the transmitted light emitted from a light source.

(Substantially Spherical Microparticles)

Substantially spherical microparticles may comprise true sphericalparticles or spherical particles with unevenness or protrusion. Arefractive index n₁ of the resin and a refractive index of n₂ of thesubstantially spherical microparticles preferably satisfy the followingformula (1):

|n ₂ −n ₁|≧0.1  (1),

more preferably the following formula (2):

|n ₂ −n ₁|≧0.15  (2), and

still preferably the following formula (3):

3.0≧|n ₂ −n ₁|≧0.2  (3).

When the refractive indices of the resin and the substantially sphericalmicroparticles forming the transparent light scattering layer satisfythe above described formulae, the light is anisotropically scattered inthe transparent light scattering layer, and thus the viewing angle canbe improved. The use of the substantially spherical microparticles willscatter the light in all directions, and thus the brightness can beimproved.

As for the substantially spherical microparticles having a highrefractive index, inorganic microparticles can be used with a refractiveindex n₂ preferably of 1.80 to 3.55, more preferably of 1.9 to 3.3, andstill preferably of 2.0 to 3.0. As for the inorganic microparticles,inorganic materials such as metallic particles by atomizing metal oxideor metal salt, diamond (n=2.42), or the like can be used. Examples ofthe metal oxide include zirconium oxide (n=2.40), oxidation zinc(n=2.40), titanium oxide (n=2.72), and cerium oxide (n=2.20), etc.Examples of the metal salts include barium titanate (n=2.40) andstrontium titanate (n=2.37), etc. As for the inorganic substantiallyspherical microparticles having a low refractive index, the referactiveindex n₂ is preferably from 1.35 to 1.80, more preferably from 1.4 to1.75, and still preferably from 1.45 to 1.7, and included therein areparticles by atomizing silica (silicon oxide; n=1.45), magnesium oxide(n=1.74), calcium carbonate (n=1.58), barium sulfate (n=1.64), or thelike. Examples of the organic substantially spherical microparticleshaving a low refractive index include an acrylic resin and a polystyreneresin. One of these substantially spherical microparticles can be usedalone or 2 of these in a combination.

Primary particles of the substantially spherical microparticles have amedian diameter, preferably of 0.1 to 500 nm, more preferably of 0.2 to300 nm, and still preferably of 0.5 to 200 nm. When the transparentsheet is used with the median diameter of the primary particles of thesubstantially spherical microparticles being within the above range, aclear image can be projected on the transparent screen since asufficient diffusion effect of the projected light is obtained withoutcompromising the transmission visibility. In the present invention, themedian diameter (D₅₀) of the primary particles of the substantiallyspherical inorganic microparticles can be determined from a particlesize distribution measured using a particle size distributionmeasurement apparatus (Trade name: DLS-8000; manufactured by OtsukaElectronics Co., Ltd.) by a dynamic light scattering method.

The content of the substantially spherical microparticles can beappropriately adjusted, depending on the thickness of the transparentlight scattering layer or the refractive index of the microparticles.The content of the microparticles in the transparent light scatteringlayer is preferably from 0.0001 to 2.0% by mass, more preferably from0.001 to 1.0% by mass, still preferably from 0.005 to 0.5% by mass,still more preferably from 0.01 to 1.0% by mass, based on the resin.When the content of the substantially spherical microparticles in thetransparent light scattering layer is within the above range, thevisibility of the projected light and the transmitted light can be bothsatisfied by sufficiently diffusing the projected light anisotropically,emitted from the projection device, while ensuring transparency of thetransparent light scattering layer.

(Transparent Reflection Layer)

The transparent reflection layer is a layer to anisotropically scatterand diffuse the projected light emitted from a light source, and thesheet-form transparent molding comprising the transparent reflectionlayer can be suitably used as a transparent reflection type transparentscreen. The visibility of the transmitted light is excellent since thetransparent reflection layer allows a perspective view. The transparentreflection layer has a refractive index n₃, larger than the refractiveindex n₁ of the resin in the transparent light scattering layer. Therefractive index n₃ of the transparent reflection layer is preferably1.8 or higher, more preferably from 1.8 to 3.0 or less, and stillpreferably from 1.8 to 2.6 or less. The projected light emitted from alight source can be effectively scattered by forming the transparentreflection layer with a material having the refractive index n₃, largerthan the refractive index n₁ of the resin in the transparent lightscattering layer. The thickness of the transparent reflection to layeris preferably from 5 to 130 nm, more preferably from 10 to 100 nm, andstill preferably from 15 to 90 nm. A reflection type transparent screenhaving a high transparency can be provided when the thickness of thetransparent reflection layer is within the above-described range.

The optical film thickness, represented by the product of the refractiveindex n₃ and film thickness d, of the transparent reflection layer ispreferably from 20 to 400 nm, more preferably from 50 to 300 nm, andstill preferably from 90 to 250 nm. When the optical film thickness ofthe transparent reflection layer is within the above-described numericalrange, an image can be clearly visualized and result in excellent colorreproducibility without color change of the reflected image.

The transparent reflection layer is preferably formed by using at leastone material selected from the group consisting of titanium oxide,niobium oxide, cerium oxide, zirconium oxide, indium tin oxide, zincoxide, tantalum oxide, zinc sulfide, and tin oxide. The use of suchmaterials will achieve the refractive index n₃ as described above andallows efficient reflection of the projected light emitted from a lightsource.

A method to form the transparent reflection layer is not particularlylimited and can be performed by a conventionally known method. Forexample, the transparent reflection layer can be formed by deposition,sputtering, or coating. The transparent reflection layer may be directlyformed on the transparent light scattering layer, or formed on a backinglayer consisted of a resin or glass and then stuck to the lightscattering layer with an adhesive, or the like.

(Backing Layer)

A backing layer is a layer for supporting the sheet-form transparentmolding, which can improve the strength of the sheet-form transparentmolding. The backing layer is preferably formed by using a highlytransparent resin or glass, which does not compromise the transmissionvisibility or the desired optical property of the sheet-form transparentmolding. For such a resin, a highly transparent resin similar to thetransparent light scattering layer described above can be used. Thatmeans, an acrylic resin, an acrylic urethane resin, a polyester acrylateresin, a polyurethane acrylate resin, an epoxy acrylate resin, apolyester resin, a polyolefin resin, a urethane resin, an epoxy resin, apolycarbonate resin, a cellulose resin, an acetal resin, a vinyl resin,a polystyrene resin, a polyamide resin, a polyimide resin, a melamineresin, a phenol resin, a silicone resin, a polyarylate resin, apolyvinyl alcohol resin, a polyvinyl chloride resin, a polysulfoneresin, and a fluorocarbon resin; a thermoset resin; an ionizingradiation-curable resin; or the like can be suitably used. Also, alaminated body or a sheet formed by layering two or more resinsdescribed above may be used. The thickness of the backing layer can beappropriately changed depending on the pupose/material so that thestrength thereof is suitable. For example, the thickness may be in therange of from 10 to 1 mm (1000 μm), or a thick board of 1 mm or more maybe possible.

(Protection Layer)

A protection layer is layered on both or either of the front side (theviewer side) and the back side of the sheet-form transparent molding,and is a layer for imparting a function such as light resistance,scratch resistance, substrate adhesiveness, and stain resistance. Theprotection layer is preferably formed by using a resin which does notcompromise the transmission visibility or the desired optical propertyof the sheet-form transparent molding.

Materials for such protection layer include, for example, polyesterresins such as a polyethylene terephthalate and a polyethylenenaphthalate; cellulosic resins such as a diacetylcellulose and atriacetylcellulose; acryl resins such as a a polymethyl methacrylate;styrene resins such as a polystyrene and an acrylonitrile-styrenecopolymer (an AS resin); a polycarbonate resin; or the like. Examples ofthe resins that forms the protection layer include: polyolefin resinssuch as a polyethylene, a polypropylene, and an ethylene-propylenecopolymer; a cyclo olefin resin or an olefin resin having a norbornenestructure; a vinyl chloride resin; amide resins such as nylon and anaromatic polyamide; an imide resin; a sulfone resin; a polyether sulfoneresin; a polyether ether ketone resin: a polyphenylene sulfide resin; avinyl alcohol resin; a vinylidene chloride resin; a vinyl butyral resin;an arylate resin; a polyoxymethylene resin; an epoxy resin; or theblends of such resins. Others include: ionizing radiation-curable resinsuch as resins of an acrylic or a urethane, an acrylic urethane or anepoxy, or a silicone; a mixture of an ionizing radiation-curable resinwith a thermoplastic resin and a solvent; a thermoset resin.

For a film forming component of the ionizing radiation-curable resincomposition, preferably, those having an acrylate functional group, forexample, those containing a relatively large amount of a monofunctionalmonomer such as ethyl (meth)acrylate, ethylhexyl (meth)acrylate,styrene, methyl styrene, N-vinylpyrrolidone and a polyfunctionalmonomer, such as polymethylolpropane tri(meth)acrylate, hexane diol(meth)acrylate, tripropylene glycol di(meth)acrylate, diethylene glycoldi(meth)acrylate, pentaerythritol tri(meth)acrylate, dipentaerythritolhexa(meth)acrylate, 1,6-hexane diol di(meth)acrylate, neopentyl glycoldi(meth)acrylate as an oligomer or a prepolymer of a polyester resin, apolyether resin, an acrylic resin, an epoxy resin, a urethane resin, analkyd resin, a spiroacetal resin, a polybutadiene resin, a polythiolpolyene resin, a (meth)acrylate of a polyfunctional compound such as apolyalcohol and a reactivity diluent having a relatively low molecularweight can be used.

In order to make the above-described ionizing radiation-curable resincomposition an ultraviolet light curable resin composition,acetophenones, benzophenons, Michler's benzoyl benzoates, α-amidoximeesters, tetramethyl thiuram monosulfides, and thioxanthones asphotopolymerization initiators, and n-butyl amine, triethylamine, andpoly-n-butylphosphine as photosensitizers may be added thereto to beused. In particular, in the present invention, a urethane acrylate as anoligomer and a dipentaerythritol hexa(meth)acrylate or the like as amonomer are preferably mixed.

An ionizing radiation-curable resin composition can be cured byirradiation of an electron beam or an ultraviolet light using a normalcuring method as a curing method. For example, in the case of electronbeam curing, an electron beam having an energy of 50 to 1000 KeV, andpreferably 100 to 300 KeV released from a variety of electron beamaccelerators such as Cockcroft-Walton-type, Van de Graaff-type,resonance transformer-type, insulating core transformer-type,linear-type, Dynamitron-type, and high-frequency-type is used, and inthe case of ultraviolet light curing, a ultraviolet light or the likeemitted from a light beam such as an ultra-high pressure mercury lamp, ahigh pressure mercury lamp, a low pressure mercury lamp, a carbon arc, axenon arc, and a metal halide lamp can be used.

A protection layer can be formed by applying a coating of theabove-described ionizing radiation (ultraviolet light)-curable resincomposition by a method such as spin coating, die coating, dip coating,bar coating, flow coating, roll coating, or gravure coating, on both oreither of the front side (viewer side) and the back side of thesheet-form transparent molding for the reflection type screen asdescribed above, and by curing the coating by the above-described means.To the surface of the protection layer, a microstructure such as aconcavoconvex structure, a prism structure, or a microlens structure canalso be provided depending on the purposes.

(Adhesive Layer)

An adhesive layer is a layer for sticking the sheet-form transparentmolding to a support. The adhesive layer is preferably formed by usingan adhesive composition which does not compromise the transmissionvisibility or the desired optical property of the sheet-form transparentmolding. Examples of the adhesive composition include a natural rubber,a synthetic rubber, an acryl resin, a polyvinyl ether resin, a urethaneresin, and a silicone resin. Specific examples of the synthetic rubberinclude a styrene-butadiene rubber, an acrylonitrile-butadiene rubber, apolyisobutylene rubber, an isobutylene-isoprene rubber, astyrene-isoprene block copolymer, a styrene-butadiene block copolymer,and a styrene-ethylene-butylene block copolymer. Specific examples ofthe silicone resin include a dimethyl polysiloxane. These adhesives canbe used singly or in combination of two or more kinds thereof. Amongthese, an acrylic adhesive is preferable.

An acrylic resin adhesive includes at least an alkyl (meth)acrylatemonomer and is formed by polymerization. Copolymerization of an alkyl(meth)acrylate monomer having an alkyl group having the number of carbonatoms of 1 to about 18 and a monomer having a carboxyl group is usuallyemployed. A (meth)acrylic acid means an acrylic acid and/or amethacrylic acid. Examples of the alkyl (meth)acrylate monomer includemethyl (meth)acrylate, ethyl (meth)acrylate, n-propyl (meth)acrylate,sec-propyl (meth)acrylate, n-butyl (meth)acrylate, sec-butyl(meth)acrylate, tert-butyl (meth)acrylate, isoamyl (meth)acrylate,n-hexyl (meth)acrylate, cyclohexyl (meth)acrylate, n-octyl(meth)acrylate, isooctyl (meth)acrylate, 2-ethylhexyl (meth)acrylate,undecyl (meth)acrylate, and lauryl (meth)acrylate. The above-describedalkyl (meth)acrylate is usually copolymerized at a ratio of 30 to 99.5parts by mass in the acrylic adhesive.

Examples of the monomer having a carboxyl group forming an acrylic resinadhesive include a monomer containing a carboxyl group such as a(meth)acrylic acid, an itaconic acid, a crotonic acid, a maleic acid, amonobutyl maleate, and β-carboxy ethyl acrylate.

With the acrylic resin adhesive, a monomer having another functionalgroup other than the above may be copolymerized as long as the propertyof the acrylic resin adhesive is not compromised. Examples of themonomer having another functional group include: a monomer having afunctional group such as a monomer containing a hydroxyl group such as2-hydroxyethyl (meth)acrylate, 2-hydroxy propyl (meth)acrylate, andallyl alcohol; a monomer containing an amide group such as(meth)acrylamide, N-methyl(meth)acrylamide, and N-ethyl(meth)acrylamide; a monomer containing a methylol group and an amidegroup such as N-methylol (meth)acrylamide and dimethylol(meth)acrylamide; a monomer containing an amino group such asaminomethyl (meth)acrylate, dimethylamino ethyl (meth)acrylate, andvinyl pyridine; a monomer containing an epoxy group such as allylglycidyl ether, or (meth)acrylate glycidyl ether. Examples of themonomer having another functional group other than the above includefluorine substituted alkyl (meth)acrylate, (meth)acrylonitrile, anaromatic compound containing a vinyl group such as styrene and methylstyrene, vinyl acetate, a halogenated vinyl compound.

For the acrylic resin adhesive, other than the monomer having afunctional group as described above, another monomer having an ethylenicdouble bond can be used. Examples of the monomer having an ethylenicdouble bond include a diester of an α,β-unsaturated dibasic acid such asdibutyl maleate, dioctyl maleate, or dibutyl fumarate; a vinyl estersuch as vinyl acetate, vinyl propionate; vinyl ether; a vinyl aromaticcompound such as styrene, α-methyl styrene, and vinyl toluene; and(meth)acrylonitrile. Other than the monomer having an ethylenic doublebond as described above, a compound having two or more ethylenic doublebonds may be used in combination. Examples of such a compound includedivinylbenzene, diallyl maleate, diallyl phthalate, ethylene glycoldi(meth)acrylate, trimethylol propane tri(meth)acrylate, and methylenebis(meth)acrylamide.

Further, other than the monomers as described above, a monomer having analkoxy alkyl chain or the like can be used. Examples of the alkoxyalkyl(meth)acrylate include 2-methoxyethyl (meth)acrylate, methoxyethyl(meth)acrylate, 2-methoxypropyl (meth)acrylate, 3-methoxypropyl(meth)acrylate, 2-methoxybutyl (meth)acrylate, 4-methoxybutyl(meth)acrylate, 2-ethoxyethyl (meth)acrylate, 3-ethoxypropyl(meth)acrylate, and 4-ethoxybutyl (meth)acrylate.

As the adhesive composition, other than the above-described acrylicresin adhesive, a homopolymer of a alkyl (meth)acrylate monomer may alsobe used. Examples of the (meth)acrylate homopolymer include methylpoly(meth)acrylate, ethyl poly(meth)acrylate, propyl poly(meth)acrylate,butyl poly(meth)acrylate, and octyl poly(meth)acrylate. Examples of acopolymer containing two types of acrylic acid ester units include ethyl(meth)acrylate-methyl (meth)acrylate copolymer, butyl(meth)acrylate-methyl (meth)acrylate copolymer, 2-hydroxyethyl(meth)acrylate-methyl (meth)acrylate copolymer, and methyl(meth)acrylate-2-hydroxy 3-phenyloxypropyl (meth)acrylate copolymer.Examples of a copolymer of a (meth)acrylic ester and another functionalmonomer include a methyl (meth)acrylate-styrene copolymer, a methyl(meth)acrylate-ethylene copolymer, and a methyl(meth)acrylate-2-hydroxyethyl (meth)acrylate-styrene copolymer.

For the adhesive, those commercially available may be used, and examplesthereof include SK-Dyne 2094, SK-Dyne 2147, SK-Dyne 1811L, SK-Dyne 1442,SK-Dyne 1435, and SK-Dyne 1415 (manufactured by Soken Chemical &Engineering Co., Ltd.), Oribain EG-655, and Oribain BPS5896(manufactured by TOYO INK CO., LTD.) or the like (trade name), which canbe suitably used.

(Reflection Protection Layer)

A reflection protection layer is a layer for preventing a reflection ora reflection of an external light on the outermost surface of thesheet-form transparent molding or a layered body thereof. The reflectionprotection layer may be layered only on one side, on the viewer side ofthe sheet-form transparent molding or the layered body thereof or theopposite side, or may be layered on both of the sides. Especially whensuch molding is used as a reflection type transparent screen, thereflection protection layer is preferably layered on the viewer side.The reflection protection layer is preferably formed by using a resinwhich does not compromise the transmission visibility or a desiredoptical property of the sheet-form transparent molding or the layeredbody thereof. For such a resin, for example, a resin cured by anultraviolet light/electron beam, i.e., an ionizing radiation-curableresin, those obtained by mixing a thermoplastic resin and a solvent toan ionizing radiation-curable resin, and a thermoset resin can be used.Among these, an ionizing radiation-curable resin is particularlypreferable.

A method of forming the reflection protection layer is not particularlylimited, and a dry coating method such as pasting of a coating film, ordirect deposition or sputtering on a film substrate; and a wet coatingtreatment method such as gravure coating, microgravure coating, barcoating, slide die coating, slot die coating, and dip coating may beused.

<Method for Manufacturing Sheet-Form Transparent Molding>

A method for manufacturing a sheet-form transparent molding according tothe present invention comprises a forming step of a transparent lightscattering layer and of a transparent reflection layer comprising alayering step when a transparent reflection layer is layered. Theforming step of the transparent light scattering layer is a step inwhich molding can be processed according to known methods such asextrusion molding comprising kneading and film manufacturing process,casting film manufacturing method, coating method such as spin coating,die coating, dip coating, bar coating, flow coating roll coating, andgravure coating, injection molding, calendering molding, blow molding,compression molding, and cell casting method; and in view of the widerange of the film thickness that can be manufactured, extrusion orinjection molding method can be suitably used. In the following, eachstep of the extrusion molding method will be described in details.

(Kneading Process)

A kneading process is a process where, using a kneading extruder, theabove-described resin and microparticles are kneaded to obtain a resincomposition. As the kneading extruder, a single- or a twin-screwkneading extruder may be used. When a twin-screw kneading machine isused, the process will be where the resin and the microparticles asabove are kneaded while applying a shear stress, preferably from 3 to1,800 KPa, more preferably from 6 to 1,400 KPa on average over the wholelength of a screw of the twin-screw kneading extruder to obtain a resincomposition. When the shear stress is within the above-described range,the microparticles can be sufficiently dispersed in the resin. Inparticular, when the shear stress is 3 KPa or higher, the dispersionhomogeneity of the microparticles can be more improved, and when theshear stress is 1,800 KPa or less, degradation of the resin isprevented, thereby preventing contamination of an air bubble in thetransparent light scattering layer. The shear stress can be set in adesired range by regulating the twin-screw kneading extruder. In thepresent invention, a resin (master batch) to which microparticles areadded in advance and a resin to which microparticles are not added maybe mixed together to be kneaded by a single- or a twin-screw kneadingextruder, thereby obtaining a resin composition. The above descriptionis one example of a kneading process, and a resin (mater batch) to whichmicroparticles are added in advance may be prepared by a single-screwextruder, or a master batch may be prepared by adding a commonly knowndispersing agent.

To the resin composition, other than the resin and the microparticles,conventionally known additives may be added as long as the transmissionvisibility or a desired optical performance of the sheet-formtransparent molding is not compromised. Examples of the additivesinclude an antioxidant, a lubricant, an ultraviolet absorber, acompatibilizer, a nucleating agent, and a stabilizer. The resin and themicroparticles are as described above.

A twin-screw kneading extruder used in the kneading process comprises acylinder and two screws therein and is configured by combining screwelements. For the screw, a flight screw at least including a conveyingelement and a kneading element is suitably used. The kneading elementpreferably includes at least one selected from the group consisting of akneading element, a mixing element, and a rotary element. By using suchflight screw including a kneading element, the microparticles can besufficiently dispersed in the resin while applying a desired shearstress.

(Film Manufacturing Process)

A film manufacturing process is a process in which a film is made of theresin composition obtained in the kneading process. A film manufacturingmethod is not particularly limited, and a sheet-form transparent moldingconsisted of a resin composition can be made by a conventionally knownmethod. For example, the resin composition obtained in the kneadingprocess is provided to a melt extruder heated to a temperature (Tm toTm+70° C.) of the melting point or higher to melt the resin composition.For the melt extruder, a single-screw extruder, a twin-screw extruder, avent extruder, or a tandem extruder can be used depending on thepurposes.

Subsequently, the molten resin composition is, for example, extrudedinto a sheet form by a die such as a T-die, and the extruded sheet-formarticle is rapidly quenched and solidified by a revolving cooling drumor the like, thereby forming a sheet-form molding. When the filmmanufacturing process is performed continuously with the above-describedkneading process, the resin composition obtained in the kneading processin a molten state may be directly extruded from a die to form asheet-form transparent light scattering layer.

The transparent light scattering layer in sheet-form obtained in thefilm manufacturing process can be further uniaxially or biaxiallystretched by a conventionally known method. Stretching of theabove-described transparent light scattering layer can improve themechanical strength.

(Layering Process)

A layering process is a process to further layer a transparentreflection layer on the sheet-form transparent light scattering layer asobtained in the film manufacturing process, in a case where atransparent reflection layer is to be provided. The method to layer thetransparent reflection layer is not particularly limited and can beperformed by a conventionally known method. For example, the transparentreflection layer can be formed by deposition, sputtering, or coating.

<Transparent Screen>

The transparent screen according to the present invention comprises thesheet-form transparent molding described above. Here, the transparentscreen comprises the transmission type and the reflection type screen.The transparent screen may only comprise the sheet-form transparentmolding described above, or may further comprise a support such as atransparent partition. The transparent screen may be planar, curved, ormay have a concave-convex surface. When the transparent screen is usedas a reflection type screen, a preferred embodiment is where the viewervisualizes an image from the transparent light scattering side of theabove-mentioned sheet-form transparent molding.

In the image display device comprising the transparent screen accordingto the present invention, the position of the light source may be at theviewer side against the screen or at the opposite side of the viewer.Such transparent screen has excellent visibility of the projected lightsince the projected light emitted from the light source is scattered andreflected anisotropically, and further has a wide viewing angle andexcellent visibility of the transmitted light.

(Support)

A support is for supporting the sheet-form transparent molding. Anysupport may be used as long as it does not compromise the transmissionvisibility or a desired optical property of the reflection type screen,and examples thereof include a transparent partition, a glass window, ahead-up display for a vehicle, and a wearable display, etc.

<Member for Vehicle>

A member for a vehicle according to the present invention comprises thesheet-form transparent molding or the transparent screen as describedabove and may be one which further comprises a reflection protectionlayer or the like. Examples of the member for a vehicle include awindshield or a side glass. When the member for a vehicle comprises thesheet-form transparent molding or the transparent screen describedabove, a clear image can be displayed on the member for a vehiclewithout providing a separate screen.

<Member for House>

A member for a house according to the present invention comprises thesheet-form transparent molding or the transparent screen described aboveand may be one which further comprises a reflection protection layer orthe like. Examples of the member for a house include a window glass fora house, a glass wall for a convenient store or a shop along the street.When the member for a house comprises the sheet-form transparent moldingor the transparent screen described above, a clear image can bedisplayed on the member for a house without providing a separate screen.

<Image Projection Device>

An image projection device according to the present invention comprisesthe above-described sheet-form transparent molding or the reflectiontype screen that allows perspective view and a projection device. Theprojection device is not particularly limited, as long as the device canproject an image on a screen, and for example, a commercially availablefront projector can be used.

FIG. 2 is a schematic diagram illustrating one embodiment of atransparent screen and an image projection device according to thepresent invention. A transparent screen 23 comprises a transparentpartition (a support) 22 and a sheet-form transparent molding 21 on thetransparent partition 22 on a viewer 24 side. The sheet-form transparentmolding 21 may include an adhesive layer to stick to the transparentpartition 22. In case of a transmission type screen, the imageprojection device comprises the transparent screen 23 and a projectiondevice 25A provided on the opposite side (the back side) of the viewer24 with respect to the transparent partition 22. A projected light 26Aemitted from the projection device 25A enters from the back side of thetransparent screen 23 and anisotropically diffuses by the transparentscreen 23, whereby the viewer 24 can visually recognize a diffused light27A. On the other hand, in case of a reflection type screen, the imageprojection device comprises the transparent screen 23 and a projectiondevice 25B provided on the same side (the front side) of the viewer 24with respect to the transparent partition 22. A projected light 26Bemitted from the projection device 25B enters from the front side of thetransparent screen 23 and anisotropically diffuses by the transparentscreen 23, whereby the viewer 24 can visually recognize a diffused light27B.

EXAMPLES

In the following, the present invention will be more specificallydescribed with reference to Examples and Comparative Examples, but thepresent invention should not be construed to be limited to the followingExamples.

The measuring methods of various physicalities and performanceevaluation in the Examples and the Comparative Examples are as follows.

(1) Haze

Haze was measured by using a turbidimeter (Part No.: NDH-5000;manufactured by NIPPON DENSHOKU INDUSTRIES CO., LTD.) in accordance withJIS K 7136.

(2) Total Light Transmittance

Total light transmittance was measured by using a turbidimeter (PartNo.: NDH-5000; manufactured by NIPPON DENSHOKU INDUSTRIES CO., LTD.) inaccordance with JIS K 7361-1.

(3) Diffusion Transmittance

Diffusion transmittance was measured by using a turbidimeter (Part No.:NDH-5000; manufactured by NIPPON DENSHOKU INDUSTRIES CO., LTD.) inaccordance with JIS K 7136-1.

(4) Reflected Frontal Luminous Intensity

Reflected frontal luminous intensity was measured by using agoniophotometer (Part No.: GC5000L; manufactured by NIPPON DENSHOKUINDUSTRIES CO., LTD.). An entering angle of a light source was set to 45degrees, and a reflected light intensity in the direction of 0 degreewhen a standard white-colored plate with whiteness degree of 95.77 wasplaced on the measuring stage was 100. When a sample was measured, theentering angle of the light source was set to 15 degrees, correspondingto a set angle of a common projector, and the intensity of the reflectedlight in the direction of 0 degree was measured.

(5) Transmitted Frontal Luminous Intensity

Transmitted frontal luminous intensity was measured by using agoniophotometer (Part No.: GC5000L; manufactured by NIPPON DENSHOKUINDUSTRIES CO., LTD.). An entering angle of a light source was set to 0degree, and a transmitted light intensity in the direction of 0 degreewith nothing placed on the measuring stage was 100. When a sample wasmeasured, the entering angle of the light source was set to 15 degrees,and the intensity of the transmitted light in the direction of 0 degreewas measured.

(6) Viewing Angle

Viewing angle was measured by using a goniophotometer (Part No.:GC5000L; manufactured by NIPPON DENSHOKU INDUSTRIES CO., LTD.). Anentering angle of a light source was set to 0 degree, and a transmittedlight intensity in the direction of 0 degree with nothing placed on themeasuring stage was 100. When a sample was measured, the transmittedlight intensity was measured by 1 degree from −85 degrees to +85 degreeswith the entering angle of the light source kept at 0 degree. Among themeasured range, the range having the transmitted light intensity of0.001 or higher was the viewing angle.

(7) Regular Reflectance

Regular reflectance was measured by using a spectrophotometer (Part No.:CM-3500d; manufactured by KONICA MINOLTA INC.). A powder materialdispersed in an appropriate solvent (water or methyl ethyl ketone) wascoated on a glass slide such that the film thickness will be 0.5 mm ormore and dried. Using this obtained glass plate with the coated film,the regular reflectance of the film-coated part from the glass surfacewas measured.

(8) Image Clarity

Image clarity is a value of definition (%) when measured by using animage clarity measuring device (Part No.: ICM-IT; manufactured by SugaTest Instruments Co., Ltd.), with an optical comb having a width of0.125 mm in accordance with JIS K7374. The larger the value of thedefinition, the higher is the transmission image clarity.

(9) Screen Performance

An image was projected on the sheet made as a transparent screen asdescribed below by using a mobile LED mini projector PP-D1S,manufactured by Onkyo Digital Solutions Corporation, from a position 50cm away in an angle of 15 degrees against a normal line direction. Then,after adjusting a focus knob of the projector to bring focus on thescreen surface, the image displayed on the screen was visually evaluatedfrom 2 places: 1 m in frontward from the screen (the same side as theprojector against the screen; so-called a front projection); and 1 mbackward from the screen (the opposite side of the projector against thescreen; so-called a rear projection), under the following evaluationcriteria. Performance as a reflection type screen can be evaluated byobserving from the front of the screen and performance as a transmissiontype screen can be evaluated by observing from the back of the screen.

[Evaluation Criteria]

⊚: A significantly clear image was visualized

◯: A clear image was visualized

Δ: An image was visualized with slightly fuzzy outline and color phase

x: An image was visualized with fuzzy outline and unsuitable to be usedas a screen

Example 1

(1) Manufacturing of Thermoplastic Resin Pellet to which Microparticlesare Added (Hereinafter Referred to as “Manufacturing Process of Pellet”)

For a thermoplastic resin pellet, a polyethylene terephthalate resin(PET) pellet (Trade Name: IP121B; manufactured by Bell PolyesterProducts, Inc.) was prepared. To this PET pellet, 0.0085% by mass offlake-form aluminum microparticles A (average diameter of the primaryparticles: 10 μm; aspect ratio: 300; regular reflectance: 62.8%), basedon the PET pellet, were added as bright flake-form microparticles andwas mixed with a rotating mixer to obtain a PET pellet in which theflake-form aluminum microparticles are uniformly adhered to the surfaceof the PET pellet.

(2) Manufacturing of Transparent Light Scattering Layer (Sheet-FormTransparent Molding) (Hereinafter Referred to as “Manufacturing Processof Sheet”)

The microparticles-added PET pellet as obtained was introduced into ahopper of a twin-screw kneading extruder (Trade Name: KZW-30MG;manufactured by TECHNOVEL CORPORATION) to make a transparent lightscattering layer (a sheet-form transparent molding) in a thickness of 80μm. The screw diameter of the twin-screw kneading extruder was 20 mm,and the active length (L/D) of the screw was 30. A hangar coat typeT-die was installed to the twin-screw kneading extruder through anadapter. The extrusion temperature was 270° C., the number of screwrevolution was 500 rpm, and the sheer stress was 300 KPa. The used screwhad the total length of 670 mm, comprised a mixing element in a portionbetween a position 160 mm and a position 185 mm from the hopper side ofthe screw and a kneading element in a portion between a position 185 mmand a position 285 mm from the hopper side of the screw, and otherportions of the screw had a flight shape.

(3) Evaluation of Transparent Screen

When the transparent light scattering layer (the sheet-form transparentmolding) as made was used directly as the transparent screen, the hazevalue was 4.3%, the diffusion transmittance was 3.7%, the total lighttransmission was 86.0%, and the transparency was high.

The transmitted frontal luminous intensity (×1000) measured with thegoniophometer was 1.02, which was found to result in excellenttransmitted frontal luminous intensity. The reflected frontal luminousintensity measured with the goniophometer was 8.9, which was found toresult in excellent reflected frontal luminous intensity. The viewingangle measured with the goniophometer was ±14 degrees, which was foundto result in excellent viewing angle property. The image clarity was92%, and the image seen transmitted through the screen was clear. Uponvisually evaluating the visibility, the image was able to be clearlyvisualized both from the front and the back, and especially, the imagewas clear when observed from the front.

Example 2

A transparent light scattering layer (a sheet-form transparent molding)in a film thickness of 100 μm was made in the same manner as Example 1,except that the added amount of the flake-form aluminum microparticles Awas changed to 0.014% by mass in the Manufacturing Process of Pellet (1)of Example 1.

When the transparent light scattering layer (the sheet-form transparentmolding) as made was used directly as the transparent screen, the hazevalue was 5.8%, the diffusion transmittance was 5.1%, the total lighttransmission was 87.4%, and the transparency was high.

The transmitted frontal luminous intensity (×1000) measured with thegoniophometer was 1.64, which was found to result in excellenttransmitted frontal luminous intensity. The reflected frontal luminousintensity measured with the goniophometer was 14.4, which was found toresult in excellent reflected frontal luminous intensity. The viewingangle measured with the goniophometer was ±17 degrees, which was foundto result in excellent viewing angle property. The image clarity was87%, and the image seen transmitted through the screen was clear. Uponvisually evaluating the visibility, the image was able to be clearlyvisualized both from the front and the back, and especially, the imagewas clear when observed from the front.

Example 3

A transparent light scattering layer (a sheet-form transparent molding)in a film thickness of 80 μm was made in the same manner as Example 1,except that the added amount of the flake-form aluminum microparticles Awas changed to 0.042% by mass in the Manufacturing Process of Pellet (1)of Example 1.

When the transparent light scattering layer (the sheet-form transparentmolding) as made was used directly as the transparent screen, the hazevalue was 17.1%, the diffusion transmittance was 12.1%, the total lighttransmission was 71.0%, and the transparency was sufficient, althoughslightly inferior to Example 2.

The transmitted frontal luminous intensity (×1000) measured with thegoniophometer was 3.51, which was found to result in excellenttransmitted frontal luminous intensity. The reflected frontal luminousintensity measured with the goniophometer was 32.0, which was found toresult in excellent reflected frontal luminous intensity. The viewingangle measured with the goniophometer was ±25 degrees, which was foundto result in excellent viewing angle property. The image clarity was82%, and the image seen transmitted through the screen was clear. Uponvisually evaluating the visibility, the image was able to be clearlyvisualized both from the front and the back, and especially, the imagewas clear when observed from the front.

Example 4

A transparent light scattering layer (a sheet-form transparent molding)in a film thickness of 100 μm was made in the same manner as Example 1,except that 0.0085% by mass of flake-form aluminum microparticles B(average diameter of the primary particles: 7 μm; aspect ratio: 40;regular reflectance: 24.6%), based on the PET pellet, was added as thebright flake-form microparticles in the Manufacturing Process of Pellet(1) of Example 1.

When the transparent light scattering layer (the sheet-form transparentmolding) as made was used directly as the transparent screen, the hazevalue was 4.1%, the diffusion transmittance was 3.6%, the total lighttransmission was 87.4%, and the transparency was high.

The transmitted frontal luminous intensity (×1000) measured with thegoniophometer was 0.85, which was found to result in excellenttransmitted frontal luminous intensity. The reflected frontal luminousintensity measured with the goniophometer was 5.7, which was found toresult in excellent reflected frontal luminous intensity. The viewingangle measured with the goniophometer was ±14 degrees, which was foundto result in excellent viewing angle property. The image clarity was92%, and the image seen transmitted through the screen was clear. Uponvisually evaluating the visibility, the image was able to be clearlyvisualized both from the front and the back, and especially, the imagewas clear when observed from the front.

Example 5

A transparent light scattering layer (a sheet-form transparent molding)in a film thickness of 100 μm was made in the same manner as Example 4,except that the added amount of the flake-form aluminum microparticles Bwas changed to 0.014% by mass in the Manufacturing Process of Pellet (1)of Example 4.

When the transparent light scattering layer (the sheet-form transparentmolding) as made was used directly as the transparent screen, the hazevalue was 6.4%, the diffusion transmittance was 5.5%, the total lighttransmission was 85.9%, and the transparency was high.

The transmitted frontal luminous intensity (×1000) measured with thegoniophometer was 1.55, which was found to result in excellenttransmitted frontal luminous intensity. The reflected frontal luminousintensity measured with the goniophometer was 7.2, which was found toresult in excellent reflected frontal luminous intensity. The viewingangle measured with the goniophometer was ±16 degrees, which was foundto result in excellent viewing angle property. The image clarity was86%, and the image seen transmitted through the screen was clear. Uponvisually evaluating the visibility, the image was able to be clearlyvisualized both from the front and the back, and especially, the imagewas clear when observed from the front.

Example 6

A transparent light scattering layer (a sheet-form transparent molding)in a film thickness of 100 μm was made in the same manner as Example 4,except that the added amount of the flake-form aluminum microparticles Bwas changed to 0.04% by mass in the Manufacturing Process of Pellet (1)of Example 4.

When the transparent light scattering layer (the sheet-form transparentmolding) as made was used directly as the transparent screen, the hazevalue was 9.4%, the diffusion transmittance was 7.3%, the total lighttransmission was 77.9%, and the transparency was sufficient, althoughslightly inferior to Example 1.

The transmitted frontal luminous intensity (×1000) measured with thegoniophometer was 1.94, which was found to result in excellenttransmitted frontal luminous intensity. The reflected frontal luminousintensity measured with the goniophometer was 19.9, which was found toresult in excellent reflected frontal luminous intensity. The viewingangle measured with the goniophometer was ±19 degrees, which was foundto result in excellent viewing angle property. The image clarity was81%, and the image seen transmitted through the screen was clear. Uponvisually evaluating the visibility, the image was able to be clearlyvisualized both from the front and the back, and especially, the imagewas clear when observed from the front.

Example 7

A transparent light scattering layer (a sheet-form transparent molding)in a film thickness of 100 μm was made in the same manner as Example 1,except that 0.010% by mass of titanium oxide (TiO₂)-coated mica (TradeName: Helios R10S; manufactured by TOPY INDUSTRIES LIMITED; averagediameter of the primary particles: 12 μm; aspect ratio: 80; regularreflectance: 16.5%) was used as the bright flake-form microparticles inthe Manufacturing Process of Pellet (1) of Example 1.

When the transparent light scattering layer (the sheet-form transparentmolding) as made was used directly as the transparent screen, the hazevalue was 2.1%, the diffusion transmittance was 1.9%, the total lighttransmission was 89.0%, and the transparency was high.

The transmitted frontal luminous intensity (×1000) measured with thegoniophometer was 0.46, which was found to result in excellenttransmitted frontal luminous intensity. The reflected frontal luminousintensity measured with the goniophometer was 4.9, which was found toresult in excellent reflected frontal luminous intensity. The viewingangle measured with the goniophometer was ±10 degrees, which was foundto result in excellent viewing angle property. The image clarity was80%, and the image seen transmitted through the screen was clear. Uponvisually evaluating the visibility, the image was able to be clearlyvisualized both from the front and the back, and especially, the imagewas clear when observed from the front.

Example 8

A transparent light scattering layer (a sheet-form transparent molding)in a film thickness of 80 μm was made in the same manner as Example 1,except that 0.0085% by mass of the flake-form aluminum microparticles Aas the bright flake-form microparticles and 0.15% by mass of zirconiumoxide (ZrO₂) particles (median diameter of the primary particles: 10 nm;refractive index: 2.40) as substantially spherical microparticles wereadded in the Manufacturing Process of Pellet (1) of Example 1.

When the transparent light scattering layer (the sheet-form transparentmolding) as made was used directly as the transparent screen, the hazevalue was 11.6%, the diffusion transmittance was 10.0%, the total lighttransmission was 86.8%, and the transparency was high.

The transmitted frontal luminous intensity (×1000) measured with thegoniophometer was 13.04, which was found to result in excellenttransmitted frontal luminous intensity. The reflected frontal luminousintensity measured with the goniophometer was 3.1, which was found toresult in excellent reflected frontal luminous intensity. The viewingangle measured with the goniophometer was ±23 degrees, which was foundto result in excellent viewing angle property. The image clarity was79%, and the image seen transmitted through the screen was clear. Uponvisually evaluating the visibility, the image was able to besignificantly clearly visualized both from the front and the back.

Example 9

A transparent light scattering layer (a sheet-form transparent molding)in a film thickness of 80 μm was made in the same manner as Example 1,except that 0.002% by mass of flake-form aluminum microparticles C(average diameter of the primary particles: 1 μm; 40 nm thick; aspectratio: 25; regular reflectance: 16.8%), based on the PET pellet, wasadded as the bright flake-form microparticles in the ManufacturingProcess of Pellet (1) of Example 1.

When the transparent light scattering layer (the sheet-form transparentmolding) as made was used directly as the transparent screen, the hazevalue was 1.8%, the diffusion transmittance was 1.6%, the total lighttransmission was 89.0%, and the transparency was high.

The transmitted frontal luminous intensity (×1000) measured with thegoniophometer was 0.79, which was found to result in excellenttransmitted frontal luminous intensity. The reflected frontal luminousintensity measured with the goniophometer was 5.0, which was found toresult in excellent reflected frontal luminous intensity. The viewingangle measured with the goniophometer was ±14 degrees, which was foundto result in excellent viewing angle property. The image clarity was83%, and the image seen transmitted through the screen was clear. Uponvisually evaluating the visibility, the image was able to be clearlyvisualized both from the front and the back, and especially, the imagewas clear when observed from the front.

Example 10

A transparent light scattering layer (a sheet-form transparent molding)in a film thickness of 80 μm was made in the same manner as Example 9,except that the added amount of the flake-form aluminum microparticles Cwas changed to 0.004% by mass in the Manufacturing Process of Pellet (1)of Example 9.

When the transparent light scattering layer (the sheet-form transparentmolding) as made was used directly as the transparent screen, the hazevalue was 3.7%, the diffusion transmittance was 3.2%, the total lighttransmission was 87.0%, and the transparency was high.

The transmitted frontal luminous intensity (×1000) measured with thegoniophometer was 1.49, which was found to result in excellenttransmitted frontal luminous intensity. The reflected frontal luminousintensity measured with the goniophometer was 6.9, which was found toresult in excellent reflected frontal luminous intensity. The viewingangle measured with the goniophometer was ±20 degrees, which was foundto result in excellent viewing angle property. The image clarity was84%, and the image seen transmitted through the screen was clear. Uponvisually evaluating the visibility, the image was able to be clearlyvisualized both from the front and the back, and especially, the imagewas clear when observed from the front.

Example 11

To one side of a transparent light scattering layer, made by a processin a similar manner as Example 10 except that the film thickness wasmade 100 μm, zinc sulfide (ZnS) was layered by deposition such that thethickness will be 40 nm and a transparent reflection layer was formed toobtain a sheet-form transparent molding.

When the sheet-form transparent molding as made was used directly as thetransparent screen, the haze value was 4.4%, the diffusion transmittancewas 3.5%, the total light transmission was 80.0%, and the transparencywas sufficient.

The transmitted frontal luminous intensity (×1000) measured with thegoniophometer was 1.02, which was found to result in excellenttransmitted frontal luminous intensity. The reflected frontal luminousintensity measured with the goniophometer was 23.3, which was found toresult in excellent reflected frontal luminous intensity. The viewingangle measured with the goniophometer was ±22 degrees, which was foundto result in excellent viewing angle property. The image clarity was75%, and the image seen transmitted through the screen was clear. Uponvisually evaluating the visibility, the image was able to be clearlyvisualized both from the front and the back, and especially, the imagewas clear when observed from the front.

Example 12

A transparent light scattering layer (a sheet-form transparent molding)in a film thickness of 100 μm was made in the same manner as Example 1,except that the added amount of titanium oxide (TiO₂)-coated mica was3.0% by mass in the Manufacturing Process of Pellet (1) of Example 7.

When the transparent light scattering layer (the sheet-form transparentmolding) as made was used directly as the transparent screen, the hazevalue was 18.2%, the diffusion transmittance was 13.1%, the total lighttransmission was 72.0%, and the transparency was sufficient, althoughslightly inferior to Example 7.

The transmitted frontal luminous intensity (×1000) measured with thegoniophometer was 3.71, which was found to result in excellenttransmitted frontal luminous intensity. The reflected frontal luminousintensity measured with the goniophometer was 36.0, which was found toresult in excellent reflected frontal luminous intensity. The viewingangle measured with the goniophometer was ±29 degrees, which was foundto result in excellent viewing angle property. The image clarity was71%, and the image seen transmitted through the screen was clear. Uponvisually evaluating the visibility, the image was able to be clearlyvisualized both from the front and the back, and especially, the imagewas clear when observed from the front.

Example 13

A transparent light scattering layer (a sheet-form transparent molding)in a film thickness of 80 μm was made in the same manner as Example 8,except that the added amount of the ZrO₂ particles was 0.001% by mass inthe Manufacturing Process of Pellet (1) of Example 8.

When the transparent light scattering layer (the sheet-form transparentmolding) as made was used directly as the transparent screen, the hazevalue was 4.6%, the diffusion transmittance was 4.0%, the total lighttransmission was 86.4%, and the transparency was high.

The transmitted frontal luminous intensity (×1000) measured with thegoniophometer was 1.02, which was found to result in excellenttransmitted frontal luminous intensity. The reflected frontal luminousintensity measured with the goniophometer was 9.2, which was found toresult in excellent reflected frontal luminous intensity. The viewingangle measured with the goniophometer was ±15 degrees, which was foundto result in excellent viewing angle property. The image clarity was88%, and the image seen transmitted through the screen was clear. Uponvisually evaluating the visibility, the image was able to besignificantly clearly visualized both from the front and the back.

Example 14

A transparent light scattering layer (a sheet-form transparent molding)in a film thickness of 80 μm was made in the same manner as Example 8,except that 0.15% by mass of acrylic resin particles (refractive index:1.51) was added as the substantially spherical microparticles instead ofthe ZrO₂ particles in the Manufacturing Process of Pellet (1) of Example8.

When the transparent light scattering layer (the sheet-form transparentmolding) as made was used directly as the transparent screen, the hazevalue was 13.1%, the diffusion transmittance was 11.1%, the total lighttransmission was 85.0%, and the transparency was high.

The transmitted frontal luminous intensity (×1000) measured with thegoniophometer was 11.20, which was found to result in excellenttransmitted frontal luminous intensity. The reflected frontal luminousintensity measured with the goniophometer was 2.8, which was found toresult in excellent reflected frontal luminous intensity. The viewingangle measured with the goniophometer was ±22 degrees, which was foundto result in excellent viewing angle property. The image clarity was73%, and the image seen transmitted to through the screen was clear.Upon visually evaluating the visibility, the image was able to besignificantly clearly visualized both from the front and the back.

Example 15

A transparent light scattering layer (a sheet-form transparent molding)in a film thickness of 20 μm was made in the same manner as Example 1,except that a PMMA pellet (Trade Name: ACRYPET VH; manufactured byMitsubishi Rayon Co., Ltd.) was used instead of the PET pellet as thethermoplastic resin and 0.85% by mass of silver particles (averagediameter of the primary particles: 1 μm; aspect ratio: 200; regularreflectance: 32.8%) was used instead of the flake-form aluminummicroparticles A as the bright flake-form microparticles in theManufacturing Process of Pellet (1) of Example 1.

When the transparent light scattering layer (the sheet-form transparentmolding) as made was used directly as the transparent screen, the hazevalue was 5.4%, the diffusion transmittance was 3.8%, the total lighttransmission was 70.1%, and the transparency was high.

The transmitted frontal luminous intensity (×1000) measured with thegoniophometer was 1.32, which was found to result in excellenttransmitted frontal luminous intensity. The reflected frontal luminousintensity measured with the goniophometer was 13.8, which was found toresult in excellent reflected frontal luminous intensity. The viewingangle measured with the goniophometer was ±15 degrees, which was foundto result in excellent viewing angle property. The image clarity was75%, and the image seen transmitted through the screen was clear. Uponvisually evaluating the visibility, the image was able to be clearlyvisualized both from the front and the back, and especially, the imagewas clear when observed from the front.

Example 16

A transparent light scattering layer (a sheet-form transparent molding)in a film thickness of 40 μm was made in the same manner as Example 1,except that a polycarbonate (PC) pellet (Trade Name: SD2201W;manufactured by Sumika Styron Polycarbonate Limited) was used instead ofthe PET pellet as the thermoplastic resin and 0.25% by mass of nickelparticles (average diameter of the primary particles: 9 μm; aspectratio: 90; regular reflectance: 16.8%) was used instead of theflake-form aluminum microparticles A as the bright flake-formmicroparticles in the Manufacturing Process of Pellet (1) of Example 1.

When the transparent light scattering layer (the sheet-form transparentmolding) as made was used directly as the transparent screen, the hazevalue was 6.3%, the diffusion transmittance was 5.2%, the total lighttransmission was 82.5%, and the transparency was high.

The transmitted frontal luminous intensity (×1000) measured with thegoniophometer was 1.14, which was found to result in excellenttransmitted frontal luminous intensity. The reflected frontal luminousintensity measured with the goniophometer was 11.3, which was found toresult in excellent reflected frontal luminous intensity. The viewing toangle measured with the goniophometer was ±18 degrees, which was foundto result in excellent viewing angle property. The image clarity was71%, and the image seen transmitted through the screen was clear. Uponvisually evaluating the visibility, the image was able to be clearlyvisualized both from the front and the back, and especially, the imageobserved from the front was clear.

Example 17

A transparent light scattering layer (a sheet-form transparent molding)in a film thickness of 10 μm was made in the same manner as Example 1,except that a cycloolefin polymer (COP) pellet (Trade Name: ZEONOR1020R; manufactured by ZEON CORPORATION) was used instead of the PETpellet as the thermoplastic resin and 0.05% by mass of flake-formalminimu microparticles D (average diameter of the primary particles: 15μm; aspect ratio: 750; regular reflectance: 68.9%) was used instead ofthe flake-form aluminum microparticles A as the bright flake-formmicroparticles in the Manufacturing Process of Pellet (1) of Example 1.

When the transparent light scattering layer (the sheet-form transparentmolding) as made was used directly as the transparent screen, the hazevalue was 3.7%, the diffusion transmittance was 3.0%, the total lighttransmission was 80.9%, and the transparency was high.

The transmitted frontal luminous intensity (×1000) measured with thegoniophometer was 2.72, which was found to result in excellenttransmitted frontal luminous intensity. The reflected frontal luminousintensity measured with the goniophometer was 8.3, which was found toresult in excellent reflected frontal luminous intensity. The viewingangle measured with the goniophometer was ±22 degrees, which was foundto result in excellent viewing angle property. The image clarity was71%, and the image seen transmitted through the screen was clear. Uponvisually evaluating the visibility, the image was able to be clearlyvisualized both from the front and the back, and especially, the imagewas clear when observed from the front.

Example 18

A microparticles-containing pellet was obtained in the same manner asExample 1, except that 0.01% by mass of titanium oxide (TiO₂)-coatedmica as the bright flake-form microparticles and 0.01% by mass of bariumtitanate (BaTiO₃) particles (median diameter of the primary particles:26 nm; refractive index: 2.40; manufactured by Kanto Denka Kogyo Co.,Ltd.) as the substantially spherical microparticles were added in theManufacturing Process of Pellet (1) of Example 1. The obtainedmicroparticles-containing pellet was used to make a transparent lightscattering layer (a sheet-form transparent molding) in a film thicknessof 500 μm with an injection molding machine (Trade Name: FNX-III;manufactured by Nissei Plastic Industrial Co., Ltd.).

When the transparent light scattering layer (the sheet-form transparentmolding) as made was used directly as the transparent screen, the hazevalue was 5.2%, the diffusion transmittance was 4.0%, the total lighttransmission was 77.5%, and the transparency was high.

The transmitted frontal luminous intensity (×1000) measured with thegoniophometer was 1.89, which was found to result in excellenttransmitted frontal luminous intensity. The reflected frontal luminousintensity measured with the goniophometer was 4.5, which was found toresult in excellent reflected frontal luminous intensity. The viewingangle measured with the goniophometer was ±24 degrees, which was foundto result in excellent viewing angle property. The image clarity was79%, and the image seen transmitted through the screen was clear. Uponvisually evaluating the visibility, the image was able to besignificantly clearly visualized both from the front and the back.

Example 19

A microparticles-containing pellet was obtained in the same manner asExample 1, except that 0.0002% by mass of flake-form aluminummicroparticles C as the bright flake-form microparticles and 0.0002% bymass of titanium oxide (TiO₂) particles (median diameter of the primaryparticles: 13 nm; refractive index: 2.72; manufactured by TAYCACORPORATION) as the substantially spherical microparticles were added inthe Manufacturing Process of Pellet (1) of Example 1. The obtainedmicroparticles-containing pellet was used to make a transparent lightscattering layer (a sheet-form transparent molding) in a film thicknessof 1000 μm with an injection molding machine (Trade Name: FNX-III;manufactured by Nissei Plastic Industrial Co., Ltd.).

When the transparent light scattering layer (the sheet-form transparentmolding) as made was used directly as the transparent screen, the hazevalue was 6.6%, the diffusion transmittance was 4.7%, the total lighttransmission was 71.5%, and the transparency was high.

The transmitted frontal luminous intensity (×1000) measured with thegoniophometer was 2.13, which was found to result in excellenttransmitted frontal luminous intensity. The reflected frontal luminousintensity measured with the goniophometer was 8.2, which was found toresult in excellent reflected frontal luminous intensity. The viewingangle measured with the goniophometer was ±17 degrees, which was foundto result in excellent viewing angle property. The image clarity was81%, and the image seen transmitted through the screen was clear. Uponvisually evaluating the visibility, the image was able to besignificantly clearly visualized both from the front and the back.

Example 20

A microparticles-containing pellet was obtained in the same manner asExample 1, except that 5.0% by mass of flake-form aluminummicroparticles E (average diameter of the primary particles: 120 μm;aspect ratio: 38; regular reflectance: 25.5%) was used instead of theflake-form aluminum microparticles A as the bright flake-formmicroparticles in the Manufacturing Process of Pellet (1) of Example 1.The obtained microparticles-containing pellet was used to make atransparent light scattering layer (a sheet-form transparent molding) ina film thickness of 500 μm with an injection molding machine (TradeName: FNX-III; manufactured by Nissei Plastic Industrial Co., Ltd.).

When the transparent light scattering layer (the sheet-form transparentmolding) as made was used directly as the transparent screen, the hazevalue was 18.5%, the diffusion transmittance was 12.2%, the total lighttransmission was 66.0%, and the transparency was sufficient, althoughslightly inferior to Example 1.

The transmitted frontal luminous intensity (×1000) measured with thegoniophometer was 10.5, which was found to result in excellenttransmitted frontal luminous intensity. The reflected frontal luminousintensity measured with the goniophometer was 28.3, which was found toresult in excellent reflected frontal luminous intensity. The viewingangle measured with the goniophometer was ±32 degrees, which was foundto result in excellent viewing angle property. The image clarity was80%, and the image seen transmitted through the screen was clear. Uponvisually evaluating the visibility, the image was able to be clearlyvisualized both from the front and the back, and especially, the imagewas clear when observed from the front.

Example 21

A transparent light scattering layer (a sheet-form transparent molding)in a film thickness of 40 μm was made in the same manner as Example 9,except that the added amount of the flake-form aluminum microparticles Cwas 0.0001% by mass in the Manufacturing Process of Pellet (1) ofExample 9.

When the transparent light scattering layer (the sheet-form transparentmolding) as made was used directly as the transparent screen, the hazevalue was 1.2%, the diffusion transmittance was 1.1%, the total lighttransmission was 95.2%, and the transparency was high.

The transmitted frontal luminous intensity (×1000) measured with thegoniophometer was 0.34, which was found to result in excellenttransmitted frontal luminous intensity. The reflected frontal luminousintensity measured with the goniophometer was 1.8, which was found toresult in excellent reflected frontal luminous intensity. The viewingangle measured with the goniophometer was ±12 degrees, which was foundto result in excellent viewing angle property. The image clarity was89%, and the image seen transmitted through the screen was clear. Uponvisually evaluating the visibility, the image was able to besignificantly clearly visualized both from the front and the back.

Example 22

A transparent light scattering layer (a sheet-form transparent molding)in a film thickness of 100 μm was made in the same manner as Example 8,except that the added amount of the ZrO₂ particles was 1.5% by mass inthe Manufacturing Process of Pellet (1) of Example 8.

When the transparent light scattering layer (the sheet-form transparentmolding) as made was used directly as the transparent screen, the hazevalue was 15.6%, the diffusion transmittance was 12.1%, the total lighttransmission was 77.3%, and the transparency was sufficient, althoughslightly inferior to Example 1.

The transmitted frontal luminous intensity (×1000) measured with thegoniophometer was 11.3, which was found to result in excellenttransmitted frontal luminous intensity. The reflected frontal luminousintensity measured with the goniophometer was 2.1, which was found toresult in excellent reflected frontal luminous intensity. The viewingangle measured with the goniophometer was ±23 degrees, which was foundto result in excellent viewing angle property. The image clarity was65%, and the image seen transmitted through the screen was clear. Uponvisually evaluating the visibility, the image was able to besignificantly clearly visualized both from the front and the back.

Comparative Example 1

A transparent light scattering layer (a sheet-form transparent molding)in a film thickness of 80 μm was made in the same manner as Example 1,except that 0.15% by mass of substantially spherical particles ZrO₂(median diameter of the primary particles: 10 nm; refractive index:2.40) were added without addition of bright flake-form microparticles inthe Manufacturing Process of Pellet (1) of Example 1.

When the transparent light scattering layer (the sheet-form transparentmolding) as made was used directly as the transparent screen, the hazevalue was 9.0%, the diffusion transmittance was 8.1%, and the totallight transmission was 90.0%. The transmitted frontal luminous intensity(×1000) measured with the goniophometer was 2.63, which was found toresult in poor transmitted frontal luminous intensity. The reflectedfrontal luminous intensity measured with the goniophometer was 1.0,which was found to result in poor reflected frontal luminous intensity.The viewing angle measured with the goniophometer was ±20 degrees, whichwas found to result in excellent viewing angle property. The imageclarity was 78%, and the image seen transmitted through the screen wasclear; however, upon visually evaluating the visibility, the brightnesswas low and a clear image was unable to be visualized, and especially,the image was unclear when observed from the front.

Comparative Example 2

A transparent light scattering layer (a sheet-form transparent molding)in a film thickness of 80 μm was made in the same manner as Example 1,except that 0.2% by mass of mica particles (Trade Name: A-21S;manufactured by YAMAGUCHI MICA CO., LTD.; average diameter of theprimary particles: 23 nm; aspect ratio: 70; regular reflectance: 9.8%)as the flake-form microparticles without brightness were added withoutaddition of bright flake-form microparticles in the ManufacturingProcess of Pellet (1) of Example 1.

When the transparent light scattering layer (the sheet-form transparentmolding) as made was used directly as the transparent screen, the hazevalue was 0.3%, the diffusion transmittance was 0.3%, and the totallight transmission was 90.0%. The transmitted frontal luminous intensity(×1000) and the reflected frontal luminous intensity measured with thegoniophometer were both 0.0, thus both transmitted light and reflectedlight were poor. The viewing angle measured with the goniophometer was±6 degrees, which was found to result in poor viewing angle property.The image clarity was 71%, and the image seen transmitted through thescreen was clear; however, upon visually evaluating the visibility, theimage was unable to be visualized both from the front and the back.

Comparative Example 3

A transparent light scattering layer (a sheet-form transparent molding)in a film thickness of 80 μm was made in the same manner as ComparativeExample 1, except that the added amount of the ZrO₂ particles were 3.0%by mass in the Manufacturing Process of Pellet (1) of Example 1.

When the transparent light scattering layer (the sheet-form transparentmolding) as made was used directly as the transparent screen, the hazevalue was 34.1%, the diffusion transmittance was 21.3%, and the totallight transmission was 62.5%.

The transmitted frontal luminous intensity (×1000) measured with thegoniophometer was 12.8, which was found to result in excellenttransmitted frontal luminous intensity. The reflected frontal luminousintensity measured with the goniophometer was 0.8, which was found toresult in excellent reflected frontal luminous intensity. The viewingangle measured with the goniophometer was ±8 degrees, which was found toresult in excellent viewing angle property. The image clarity was 43%,and the image seen transmitted through the screen was clear. Uponvisually evaluating the visibility, the image was unable to bevisualized both from the front and the back.

The details of the transparent light scattering layers used in theExamples and the Comparative Examples are shown in Table 1.

TABLE 1 Transparent light scattering layer Resin Flake-formmicroparticles Refractive Average Regular Content index diameter Aspectreflectance [% by Type n₁ [—] Type Brilliance [μm] ratio [%] mass]Example 1 PET 1.68 Aluminum A Yes 10 300 62.8 0.0085 Example 2 PET 1.68Aluminum A Yes 10 300 62.8 0.014 Example 3 PET 1.68 Aluminum A Yes 10300 62.8 0.042 Example 4 PET 1.68 Aluminum B Yes 7 40 24.6 0.0085Example 5 PET 1.68 Aluminum B Yes 7 40 24.6 0.014 Example 6 PET 1.68Aluminum B Yes 7 40 24.6 0.04 Example 7 PET 1.68 TiO₂-coated Yes 12 8016.5 0.1 mica Example 8 PET 1.68 Aluminum A Yes 10 300 62.8 0.0085Example 9 PET 1.68 Aluminum C Yes 1 25 16.8 0.002 Example 10 PET 1.68Aluminum C Yes 1 25 16.8 0.004 Example 11 PET 1.68 Aluminum C Yes 1 2516.8 0.004 Example 12 PET 1.68 TiO₂-coated Yes 12 80 16.5 3 mica Example13 PET 1.68 Aluminum A Yes 10 300 62.8 0.0085 Example 14 PET 1.68Aluminum A Yes 10 300 62.8 0.0085 Example 15 PMMA 1.49 Silver Yes 1 20032.8 0.85 Example 16 PC 1.59 Nickel Yes 9 90 16.8 0.25 Example 17 COP1.53 Aluminum D Yes 15 750 68.9 0.05 Example 18 PET 1.68 TiO₂-coated Yes12 80 16.5 0.01 mica Example 19 PET 1.68 Aluminum C Yes 1 25 16.8 0.0002Example 20 PET 1.68 Aluminum E Yes 120 38 25.5 5.0 Example 21 PET 1.68Aluminum C Yes 1 25 16.8 0.0001 Example 22 PET 1.68 Aluminum A Yes 10300 62.8 0.0085 Comparative PET 1.68 — — — — — — Example 1 ComparativePET 1.68 Mica A-21S No 23 70 9.8 0.2 Example 2 Comparative PET 1.68 — —— — — — Example 3 Transparent light Transparent reflection layerscattering layer Optical film Substantially spherical thicknessmicroparticles (refractive Refractive Content Refractive Film index ×film index [% by Thickness index thickness thickness) Type n₂ [—] mass][μm] Type n₃ [—] [nm] [nm] Example 1 — — — 80 — — — — Example 2 — — —100 — — — — Example 3 — — — 80 — — — — Example 4 — — — 100 — — — —Example 5 — — — 100 — — — — Example 6 — — — 100 — — — — Example 7 — — —100 — — — — Example 8 ZrO₂ 2.40 0.15 80 — — — — Example 9 — — — 80 — — —— Example 10 — — — 80 — — — — Example 11 — — — 100 ZnS 2.37 40 94.8Example 12 — — — 100 — — — — Example 13 ZrO₂ 2.40 0.001 80 — — — —Example 14 Acryl 1.51 0.15 80 — — — — Example 15 — — — 20 — — — —Example 16 — — — 40 — — — — Example 17 — — — 10 — — — — Example 18BaTiO₃ 2.40 0.01 500 — — — — Example 19 TiO₂ 2.72 0.0002 1000 — — — —Example 20 — — — 500 — — — — Example 21 — — — 40 — — — — Example 22 ZrO₂2.40 1.5 100 — — — — Comparative ZrO₂ 2.40 0.15 80 — — — — Example 1Comparative — — — 80 — — — — Example 2 Comparative ZrO₂ 2.40 3.0 80 —Example 3

Various physicalities and the results of performance evaluation of thesheet-form transparent moldings in the Examples and the ComparativeExamples are shown in Table 2.

TABLE 2 Sheet-form transparent molding Screen Performance TransmittedObservation Frontal Reflected Observation form the Diffusion Total lightluminous Frontal Image from the back front Haze transmittancetransmittance intensity × luminous Viewing Clarity (Transmission(Reflection [%] [%] [%] 1000 intensity angle [%] type) type) Example 14.3 3.7 86.0 1.02 8.9 ±14 92 ◯ ⊚ Example 2 5.8 5.1 87.4 1.64 14.4 ±17 87◯ ⊚ Example 3 17.1 12.1 71.0 3.51 32.0 ±25 82 ◯ ⊚ Example 4 4.1 3.6 87.40.85 5.7 ±14 92 ◯ ⊚ Example 5 6.4 5.5 85.9 1.55 7.2 ±16 86 ◯ ⊚ Example 69.4 7.3 77.9 1.94 19.9 ±19 81 ◯ ⊚ Example 7 2.1 1.9 89.0 0.46 4.9 ±10 80◯ ⊚ Example 8 11.6 10.0 86.8 13.04 3.1 ±23 79 ⊚ ⊚ Example 9 1.8 1.6 89.00.79 5.0 ±14 83 ◯ ⊚ Example 10 3.7 3.2 87.0 1.49 6.9 ±20 84 ◯ ⊚ Example11 4.4 3.5 80.0 1.02 23.3 ±22 75 ◯ ⊚ Example 12 18.2 13.1 72.0 3.71 36.0±29 71 ◯ ⊚ Example 13 4.6 4.0 86.4 1.20 9.2 ±15 88 ⊚ ⊚ Example 14 13.111.1 85.0 11.20 2.8 ±22 73 ⊚ ⊚ Example 15 5.4 3.8 70.1 1.32 13.8 ±15 75◯ ⊚ Example 16 6.3 5.2 82.5 1.14 11.3 ±18 71 ◯ ⊚ Example 17 3.7 3.0 80.92.72 8.3 ±22 71 ◯ ⊚ Example 18 5.2 4.0 77.5 1.89 4.5 ±24 79 ⊚ ⊚ Example19 6.6 4.7 71.5 2.13 8.2 ±17 81 ⊚ ⊚ Example 20 18.5 12.2 66.0 10.5 28.3±32 80 ◯ ⊚ Example 21 1.2 1.1 95.2 0.34 1.8 ±12 89 ◯ ◯ Example 22 15.612.1 77.3 11.3 2.1 ±23 65 ⊚ ⊚ Comparative 9.0 8.1 90.0 2.63 1.0 ±20 78 ΔX Example 1 Comparative 0.3 0.3 90.0 0.00 0.0 ±6 71 X X Example 2Comparative 34.1 21.3 62.5 12.8 0.8 ±8 43 X X Example 3

DESCRIPTION OF SYMBOLS

-   -   11 Transparent light scattering layer    -   12 Bright flake-form microparticle    -   13 Substantially spherical microparticle    -   14 Resin    -   15 Transparent reflection layer    -   21 Transparent sheet (transparent light scattering layer)    -   22 Transparent partition (support)    -   23 Transparent screen    -   24 Viewer    -   25A, 25B Projection device    -   26A, 26B Projected light    -   27A, 27B Scattered light

1-28. (canceled)
 29. A sheet-form transparent molding comprising atransparent light scattering layer comprising a resin and brightflake-form microparticles, wherein the content of the bright flake-formmicroparticles is from 0.0001 to 1.0% by mass based on the resin, anaverage diameter of primary particles of the bright flake-formmicroparticles is from 0.05 to 30 μm and an average aspect ratio of thebright flake-form microparticles is from 10 to 800, the brightflake-form microparticles are metallic particles selected from the groupconsisting of aluminum, silver, copper, platinum, gold, titanium,nickel, tin, indium and chromium, or a bright material of glass coatedwith those metals, the total light transmittance of the sheet-formtransparent molding is 70% or higher, the haze value of the sheet-formtransparent molding is from 1% to 30% or less, the image clarity of thesheet-form transparent molding is 70% or higher.
 30. The sheet-formtransparent molding according to claim 29, wherein the regularreflectance of the bright flake-form microparticles is 12% or higher.31. The sheet-form transparent molding according to claim 29, whereinthe transparent light scattering layer further comprises substantiallyspherical microparticles.
 32. The sheet-form transparent moldingaccording to claim 31, wherein the difference between a refractive indexn₂ of the substantially spherical microparticles and a refractive indexn₁ of the resin satisfies the following formula (1):|n ₁ −n ₂|≧0.1  (1), a median diameter of primary particles of thesubstantially spherical microparticles is from 0.1 to 500 nm, thecontent of the substantially spherical microparticles is from 0.0001 to2.0% by mass based on the resin.
 33. The sheet-form transparent moldingaccording to claim 31, wherein the substantially sphericalmicroparticles are at least one selected from the group consisting ofzirconium oxide, zinc oxide, titanium oxide, cerium oxide, bariumtitanate, strontium titanate, magnesium oxide, calcium carbonate, bariumsulfate, diamond, a cross-linked acrylic resin, a cross-linked styreneresin, and silica.
 34. The sheet-form transparent molding according toclaim 29, further comprising a transparent reflection layer having arefractive index n₃, larger than the refractive index n₁ of the resin,on one face of the sheet-form transparent molding.
 35. The sheet-formtransparent molding according to claim 34, wherein the refractive indexn₃ of the transparent reflection layer is 1.8 or higher, the opticalfilm thickness represented by the product of the refractive index n₃ andfilm thickness d of the transparent reflection layer is from 20 to 400nm.
 36. The sheet-form transparent molding according to claim 34,wherein the transparent reflection layer comprises at least one selectedfrom the group consisting of titanium oxide, niobium oxide, ceriumoxide, zirconium oxide, indium tin oxide, zinc oxide, tantalum oxide,zinc sulfide, and tin oxide.
 37. The transmission type transparentscreen comprising the sheet-form transparent molding according to claim29.
 38. The reflection type transparent screen comprising the sheet-formtransparent molding according to claim
 29. 39. A laminated bodycomprising the sheet-form transparent molding according to claim
 29. 40.A member for a vehicle, comprising the sheet-form transparent moldingaccording to claim
 29. 41. A member for a house, comprising thesheet-form transparent molding according to claim
 29. 42. An imageprojection device, comprising the sheet-form transparent moldingaccording to claim 29, and a projection device.